A. Field of the Invention
The invention relates to a surgical method of treating hip diseases. More specifically, the invention provides an innominate osteotomy for treating diseases such as Legg-Calve-Perthes Disease, developmental hip dysplasia, or hip dislocation.
B. Description of the Prior Art
Legg-Calve-Perthes disease is a self-limiting hip disorder caused by a varying degree of ischemia and subsequent necrosis of the femoral head. Signs of the disorder include avascular necrosis of the proximal femoral epiphysis nucleus, abnormal growth of the physis, and eventual remodeling of regenerated bone. Typically, avascular necrosis of the femoral epiphysis results in delayed occific nucleus. Articular cartilage is nourished by synovial fluid and continues to grow. Consequently, cartilage columns become distorted with some loss of cellular components and do not undergo normal ossification. This results in an excess of calcified cartilage in the primary trabecular bone. Symptoms occur with subchondral collapse and fracture.
The incidence of Legg-Calve-Perthes disease is generally greater in males than females with a male to female ratio of 4-5 to 1. Generally, Legg-Calve-Pertes disease is found in young boys (4 to 8 years old) with delayed skeletal maturity. The age at which treatment is initiated appears to be the key to a good prognosis. If detected and treated after 8 years of age, the prognosis tends to be poor.
Developmental hip dysplasia involves displacement of the femoral head from the acetabulum, which disrupts the normal development of the hip joint. Developmental hip dysplasia is estimated to occur in 1-1.5 cases per 1000 live births and includes a wide spectrum of abnormalities ranging from simple hip instability with capsula laxity to complete displacement of the femoral head from an anomalous acetabular socket. Thus, the term dysplasia includes a developmental abnormality of the hip joint in which the capsule, the proximal femur, and/or the acetabulum are defective.
Innominate osteotomy has been used to treat Legg-Calve-Perthes disease and developmental dysplasia of the hip. A widely used procedure was developed in 1961 by Robert Salter and is called a Salter osteotomy or Salter""s innominate osteotomy. The objective of Salter""s innominate osteotomy is to derotate the maldirected acetabulum and correct excessive acetabular antetorsion. Stability is thus improved by providing anatomic coverage of the femoral head by anterior and superolateral portions of the acetabulum in the weight bearing position.
Although successful in many cases, the Salter technique has many complications, such as loss of fixation with displacement of the distal fragment, stiffness, and loss of hip flexion. Also the patient generally requires two operations, one to perform the osteotomy and a second to remove the metal pins or screws.
The present invention provides a surgical method of treating hip diseases, including Legg-Calve-Perthes Disease, developmental hip dysplasia, and/or hip dislocation. The method includes a series of surgical procedures including a transverse osteotomy of the posterior portion of supraacetabular portion, an oblique and inclined osteotomy of the anterior portion of the supraacetabulum, detachment of a bone graft from iliac crest, anterolateral displacement of a distal section of the ilium, and insertion of the bone graft into the exposed opening of the osteotomy site.
The procedure rotates the distal section of the osteotomy site laterally and anteriorly, increasing coverage of the acetabulum over the femoral head. The procedure also establishes better concentric reduction in hips with dysplasia or dislocation. It also increases coverage of the acetabulum over the femoral head in hips with Legg-Calve-Perthes diseases to achieve better stability and remodeling of the femoral head. Additionally, the technique reduces complications by providing stability without the use of metal pins or screws. Furthermore, a patient can undergo rehabilitation earlier than with a Salter osteotomy, in part because a secondary operation is not necessary.